Command-line interface for all installation-related commands

[muffato]

shpc install software              # install latest
shpc install software:version

shpc uninstall software            # uninstall all installed version
shpc uninstall software:version    # doesn't complain if that version isn't installed yet

shpc reinstall software            # reinstall all installed versions of that software
shpc reinstall software:version    # reinstall only that version
shpc reinstall --all               # reinstall all installed versions of all software

[muffato]

About shpc upgrade software

1. If software is not installed yet: ask user to "install" it
2. Else, follow this logic:

For each version already installed:
    If version == latest:
        currently just skip, in the future check the checksum of the container
    Else:
        ask the user about uninstalling it
If latest version was not installed yet:
   install the latest

Also needs:

• --all option to do the above for all software
• --dry-run option to show which versions would be uninstalled and installed